An integrative, multiscale view on neural theories of consciousness

Neuron, Journal Year: 2024, Volume and Issue: 112(10), P. 1531 - 1552

Published: March 5, 2024

How is conscious experience related to material brain processes? A variety of theories aiming answer this age-old question have emerged from the recent surge in consciousness research, and some are now hotly debated. Although most researchers so far focused on development validation their preferred theory relative isolation, article, written by a group scientists representing different theories, takes an alternative approach. Noting that various often try explain aspects or mechanistic levels consciousness, we argue do not necessarily contradict each other. Instead, several them may converge fundamental neuronal mechanisms be partly compatible complementary, multiple can simultaneously contribute our understanding. Here, consider unifying, integration-oriented approaches been largely neglected, seeking combine valuable elements theories.

Language: Английский

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Consciousness and sleep

Neuron, Journal Year: 2024, Volume and Issue: 112(10), P. 1568 - 1594

Published: May 1, 2024

Language: Английский

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Thalamic contributions to the state and contents of consciousness

Neuron, Journal Year: 2024, Volume and Issue: 112(10), P. 1611 - 1625

Published: May 1, 2024

Consciousness can be conceptualized as varying along at least two dimensions: the global state of consciousness and content conscious experience. Here, we highlight cellular systems-level contributions thalamus to then argue for thalamic content, including integrated, segregated, continuous nature our We underscore vital, yet distinct roles core- matrix-type neurons. Through reciprocal interactions with deep-layer cortical neurons, matrix neurons support wakefulness determine perceptual thresholds, whereas core maintain enable constancy. further propose that integration, segregation, continuity depend on convergent corticothalamic projections enabling dimensionality reduction, a reticular nucleus-mediated divisive normalization-like process, sustained coherent activity in thalamocortical loops, respectively. Overall, conclude plays central topological role brain structures controlling

Language: Английский

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DySCo: A general framework for dynamic functional connectivity

PLoS Computational Biology, Journal Year: 2025, Volume and Issue: 21(3), P. e1012795 - e1012795

Published: March 7, 2025

A crucial challenge in neuroscience involves characterising brain dynamics from high-dimensional recordings. Dynamic Functional Connectivity (dFC) is an analysis paradigm that aims to address this challenge. dFC consists of a time-varying matrix (dFC matrix) expressing how pairwise interactions across areas change over time. However, the main approaches have been developed and applied mostly empirically, lacking common theoretical framework clear view on interpretation results derived matrices. Moreover, community has not using most efficient algorithms compute process matrices efficiently, which prevented showing its full potential with datasets and/or real-time applications. In paper, we introduce Symmetric Matrix (DySCo), associated repository. DySCo presents commonly used measures language implements them computationally way. This allows study activity at different spatio-temporal scales, down voxel level. provides single to: (1) Use as tool capture interaction patterns data form easily translatable imaging modalities. (2) Provide comprehensive set quantify properties evolution time: amount connectivity, similarity between matrices, their informational complexity. By combining it possible perform analysis. (3) Leverage Temporal Covariance EVD algorithm (TCEVD) store eigenvectors values then also EVD. Developing eigenvector space orders magnitude faster more memory than naïve space, without loss information. The methodology here validated both synthetic dataset rest/N-back task experimental fMRI Human Connectome Project dataset. We show all proposed are sensitive changes configurations consistent time subjects. To illustrate computational efficiency toolbox, performed level, demanding but afforded by TCEVD.

Language: Английский

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Cortico-thalamo-cortical interactions modulate electrically evoked EEG responses in mice

eLife, Journal Year: 2023, Volume and Issue: 12

Published: Feb. 9, 2023

Perturbational complexity analysis predicts the presence of consciousness in volunteers and patients by stimulating brain with brief pulses, recording EEG responses, computing their spatiotemporal complexity. We examined underlying neural circuits mice directly cortex while Neuropixels probes during wakefulness isoflurane anesthesia. When are awake, stimulation deep cortical layers reliably evokes locally a pulse excitation, followed biphasic sequence 120 ms profound off period rebound excitation. A similar pattern, partially attributed to burst spiking, is seen thalamic nuclei associated pronounced late component evoked EEG. infer that cortico-thalamo-cortical interactions drive long-lasting signals elicited awake state. The EEG, reduced running absent

Language: Английский

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Mitofusin-2 in nucleus accumbens D2-MSNs regulates social dominance and neuronal function

Cell Reports, Journal Year: 2023, Volume and Issue: 42(7), P. 112776 - 112776

Published: July 1, 2023

The nucleus accumbens (NAc) is a brain hub regulating motivated behaviors, including social competitiveness. Mitochondrial function in the NAc links anxiety with competitiveness, and mitochondrial fusion protein mitofusin 2 (Mfn2) neurons regulates anxiety-related behaviors. However, it remains unexplored whether accumbal Mfn2 levels also affect behavior actions emotional domain are driven by distinct cell types. Here, we found that subordinate-prone highly anxious rats show decreased overexpression promotes dominant behavior. In mice, selective downregulation dopamine D2 receptor-expressing medium spiny (D2-MSNs) induced subordination, accompanied functions excitability D2-MSNs. Instead, D1-MSN-targeted affected competitive ability only transiently likely because of an increase anxiety-like Our results assign dissociable cell-type specific roles to modulating dominance anxiety.

Language: Английский

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Behavioral and cortical arousal from sleep, muscimol-induced coma, and anesthesia by direct optogenetic stimulation of cortical neurons

iScience, Journal Year: 2024, Volume and Issue: 27(6), P. 109919 - 109919

Published: May 7, 2024

Highlights•Optogenetic activation of cortical neurons wakes up mice from NREM and REM sleep•Awakenings are induced more effectively in posterior parietal than prefrontal cortex•Cortical opto stimulation causes EEG behavioral arousal coma•Cortical during deep sevo-dex anesthesiaSummaryThe cerebral cortex is widely considered part the neural substrate consciousness, but direct causal evidence missing. Here, we tested whether optogenetic (PtA) or medial (mPFC) sufficient for three states characterized by progressively deeper unresponsiveness: sleep, a coma-like state muscimol injection midbrain, sevoflurane-dexmedetomidine anesthesia. We find that always awakens both sleep with PtA requiring weaker/shorter light pulses mPFC. Moreover, most cases produce (decrease low frequencies) (recovery righting reflex) brainstem coma, as well These findings provide and/or anesthesia.Graphical abstract

Language: Английский

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Sleep-like cortical dynamics during wakefulness and their network effects following brain injury

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Aug. 22, 2024

By connecting old and recent notions, different spatial scales, research domains, we introduce a novel framework on the consequences of brain injury focusing key role slow waves. We argue that long-standing finding EEG waves after reflects intrusion sleep-like cortical dynamics during wakefulness; illustrate how these are generated they can lead to functional network disruption behavioral impairment. Finally, outline scenario whereby post-injury be modulated reawaken parts have fallen asleep optimize rehabilitation strategies promote recovery. In this Perspective, authors propose result in slowing wakefulness. The generation their effects networks behavior discussed, as well future directions for neuromodulation.

Language: Английский

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Exploring effects of anesthesia on complexity, differentiation, and integrated information in rat EEG

Neuroscience of Consciousness, Journal Year: 2024, Volume and Issue: 2024(1)

Published: Jan. 1, 2024

To investigate mechanisms underlying loss of consciousness, it is important to extend methods established in humans rodents as well. Perturbational complexity index (PCI) a promising metric "capacity for consciousness" and based on perturbational approach that allows inferring system's capacity causal integration differentiation information. These properties have been proposed necessary conscious systems. Measures spontaneous electroencephalography recordings, however, may be more practical certain clinical purposes better reflect ongoing dynamics. Here, we compare PCI (using electrical stimulation perturbing cortical activity) several electroencephalography-based measures signal diversity integrated information rats undergoing propofol, sevoflurane, ketamine anesthesia. We find that, along with PCI, the measures, Lempel-Ziv (LZ) geometric (Φ

Language: Английский

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Investigating the Impact of Local Manipulations on Spontaneous and Evoked Brain Complexity Indices: A Large-Scale Computational Model

Applied Sciences, Journal Year: 2024, Volume and Issue: 14(2), P. 890 - 890

Published: Jan. 20, 2024

Brain complexity relies on the integrity of structural and functional brain networks, where specialized areas synergistically cooperate a large scale. Local alterations within these can lead to widespread consequences, leading reduction in overall network complexity. Investigating mechanisms governing this occurrence exploring potential compensatory interventions is pressing research focus. In study, we employed whole-brain silico model simulate large-scale impact local node alterations. These were assessed by metrics derived from both model’s spontaneous activity (i.e., Lempel–Ziv (LZc)) its responses simulated perturbations Perturbational Complexity Index (PCI)). Compared LZc, silencing distinct regions induced that paralleled systematic drop PCI. Specifically, while intact engaged complex interactions closely resembling those obtained empirical studies, it displayed reduced PCI values across all manipulations. This approach also revealed heterogeneous different manipulations alterations, emphasizing importance posterior hubs sustaining work marks an initial stride toward comprehensive exploration underlying loss recovery conditions.

Language: Английский

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